From: Eric Botcazou <ebotca...@adacore.com>
The problem is that the order of components listed in a constant CONSTRUCTOR
does not match that of the associated record type.
gcc/ada/ChangeLog:
* gcc-interface/utils2.cc (compare_elmt_bitpos): Deal specially with
0-sized components when the bit position is the same.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/gcc-interface/utils2.cc | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/gcc/ada/gcc-interface/utils2.cc b/gcc/ada/gcc-interface/utils2.cc
index 8eebf593596..e91f67d7e45 100644
--- a/gcc/ada/gcc-interface/utils2.cc
+++ b/gcc/ada/gcc-interface/utils2.cc
@@ -2113,7 +2113,23 @@ compare_elmt_bitpos (const void *rt1, const void *rt2)
const int ret
= tree_int_cst_compare (bit_position (field1), bit_position (field2));
- return ret ? ret : (int) (DECL_UID (field1) - DECL_UID (field2));
+ if (ret)
+ return ret;
+
+ /* The bit position can be the same if one of the fields has zero size.
+ In this case, if the other has nonzero size, put the former first to
+ match the layout done by components_to_record. Otherwise, preserve
+ the order of the source code. */
+
+ const bool field1_zero_size = integer_zerop (DECL_SIZE (field1));
+ const bool field2_zero_size = integer_zerop (DECL_SIZE (field2));
+
+ if (field1_zero_size && !field2_zero_size)
+ return -1;
+ else if (!field1_zero_size && field2_zero_size)
+ return 1;
+ else
+ return (int) (DECL_UID (field1) - DECL_UID (field2));
}
/* Return a CONSTRUCTOR of TYPE whose elements are V. */
--
2.43.0
